External radiation exposure

Cosmic radiation

A substantial part of the ionising radiation people are exposed to, originates from cosmic radiation. It reaches the earth from the sun and from deep space and is mainly composed of high energy particles and gamma radiation. On its way through the atmosphere, cosmic radiation is partially absorbed. Thus, the intensity of cosmic radiation depends on altitude. It is lowest at sea level and increases with the altitude of a site. On the Zugspitze it is four times higher than at the coast. Airplanes cannot be shielded against cosmic radiation. Thus, people are exposed to this type of radiation during a flight.

Radioactive substances in building materials

Rocks and soils are important resources for mineral building materials, such as bricks and concrete. The radionuclides present in the rocks pass into the building materials and in this way add to the external radiation exposure.

Natural radiation exposure in Germany

The total natural radiation exposure in Germany amounts to 2.1 millisieverts per year on average (effective dose). Depending on the place of residence, dietary and lifestyle habits, it ranges from 1 to 10 millisieverts.

Artificial radionuclides in the environment make you think of reactor disasters as they occurred in Chernobyl and in Fukushima. However, artificial radionuclides were also released during nuclear weapons tests. Small amounts of radionuclides are released from nuclear installations during normal operation as well. The release is strictly monitored by various measuring networks.